Check strap



Nov. 2, 1948. H. JJSHIVELL 2,452,690

CHECK STRAP Filed Nov. 27, 1945 4 INVENTOR. Homer ,1 fi'hivell ATTORNEYS Patented Nov. 2, 1948 UNITED STATES FA'EEQN'E 4 Claims.

This invention relates to check straps for automatic looms and more particularly to an improved check strap for the new high speed automatic looms.

The checking of the movement of the picker stick in automatic or under-pick looms is usually effected by means of a strap in the form of a loop which encompasses a part of the path of travel of the picker stick but which is substantially shorter than the full length of the encompassed part of said picker stick path. Where the loom has been rigidly attached to the frame at one side of the path of travel of the picker stick, the energy of the imp-act of the picker stick against the loop, as it approaches each end of its path of travel, has been taken up in the flexing of the stifily flexible material of the strap and in the friction of the picker stick against the strap. In cases-where check straps have been made in the form of endless rotating loops, a part of the energy of the impact has been absorbed as friction between such strap and its supports. The combination of the repeated flexing of the strap, the high tensional stresses, the internal friction resulting from the impact, the surface friction with its incidental abrasion and the heating which results from the internal and surface friction and from the flexing, all tend to rapid deterioration ofthe check strap and consequently it has been necessary frequently to replace these straps.

Various improvements have been made in check strap constructions to increase the life thereof, such, for example, as those shown in my prior Patents 1,993,531, granted March 5 1935, and 2,374,042, granted April 17, 1945. These improvements have materially increased the durability and efficiency of such straps when used upon automatic looms; but such check straps still are subject to deterioration due to rapid flexing on high speed automatic looms with consequent overheating.

By the present invention I have increased the useful life of check straps by a change which would have been expected to weaken the belt. The explanation of this apparent contradiction is that I have overcome to a considerable extent this tendency to overheating of check straps by providing for increased ventilation thereof and increased surface from which to remove the heat resulting from the high speed of operation. To this end the present invention aims to provide ventilating openings in those parts of the check strap loop which are subjected to impact and/or flexing and/or friction in the picker stick check- I ing action, whereby the movement of these strap parts in the picker stick checking action will effect a circulation of air through these openings and thus carry away the excess heat developed, thereby preventing deterioration of the strap from overheating.

Important features of the invention and other objects thereof to which attention has not specifically been directed hereinabove will appear hereinafter when the following description and claims are considered in connection with the accompanying drawings, in which Figure 1 is a fragmentary View in side elevation illustrating certain parts of the picker mechanism of a loom having a check strap embodying the invention applied thereto;

Figure 2 is a detail view in elevation illustrating a check strap of the type shown in my prior Le ters Patent No. 1,993,531 but embodying the present invention and detached from the machine;

Figures 3-5 are views similar to Figure 2 but showing modified constructions and arrangements of the ventilating openings in the strap; and

Figure 6 is a perspective view of a continuous loop check strap having the invention embodied therein.

In the drawing the invention is shown applied to the picker mechanism of a loom comprising a fixed shuttle guide 2, a shuttle i mounted for reciprocating movement upon said shuttle guide, a picker stick 6 arranged for oscillating movement, and a picker head it mounted on the picker stick for engagement with the shuttle.

In the form of the invention shown in Figures 2, 3 and 4, the check strap i2 is of the curved construction described and claimed in my Letters Patent No. 1,993,531. This insures that the strap, when bent into the elliptical form shown in Figure 1, with its ends secured in place on thebracket it, will present contact faces at the ends of the loop which are inclined at substantially the same angles as the angles of inclination of the contact faces of the picker stick 6 when the picker stick is at the limits of its swinging movements. It will be apparent, of course, that the radius of curvature of the strap may be varied to adapt the same to the requirements of difierent looms, or the old-fashioned straight straps can be ventilated according to this invention.

It will be understood that any one or all of the straps i2 shown in Figures 2, 3 and 4 may be provided with a supplemental strap as set forth in my Patent No. 2,374,042.

In accordance with the present invention, ad-

vantage is taken of the movements necessarily imparted to those parts of the strap which take part in the checking action to efiect a circulation of a cooling fluid through the strap. As herein shown, provision is made for such circulation by providing ventilating openings [8, l8, [8 l8, etc., through the strap. These openings, as shown, are arranged so that air forced to circulate therethrough will remove the heat generated by the checking action of this strap. They are also so arranged that they Will not materially shorten the life of the strap by reason of the removal of the material to form the openings.

In the form of the invention shown in Figure 2, the openings 18 and I8 are shown as arranged in pairs in the same vertical sections of the strap but the openings through those parts of the strap which are at the ends of the loop Where impact takes place are shown as smaller than the openings at the side of the loop. Because of the greater extent of movement of the loop ends the smaller openings will permit adequate circulation of cooling air therethrough.

In Figure 3 only one opening 18 occurs in any one vertical section of the loop, these openings being of substantially uniform size and distributed uniformly throughout the length of the strap, successive openings being, however, ofiset vertically and longitudinally.

In the form of the invention shown in Figure 4, the openings l8 are of a somewhat different shape, comprising essentially two V-shaped openings with their apices substantially meeting.

In Figure 5 of the drawings the openings l8 and 18 are shown as comprising a single rela tively elongated slot in the upper half of the strap and a shorter slot in the lower half.

In Figure 6 the invention is shown as applied to a check strap 2 of the endless rotating 100p type. In this type of check strap there is a constant gradual rotation of the strap in its mountings, with the result that no one part of the strap constantly receives the impact of the picker stick. In providing for ventilation of this strap, therefore, it is desirable that the ventilating openings H; be substantially uniformly distributed throughout the periphery of the strap. As herein shown the upper openings are somewhat longer than the lower openings and are staggered with respect to the lower openings. upper circumference of the strap shown in Figure 6 is greater than the lower circumference, this ratio in the sizes of the openings has advantage. As in the forms of the invention described in Figures 1 to inclusive, the flexing of the Since the 4 insure movement of the air through the openings I 8 therein.

From the foregoing description it will be seen that the invention provides in a simple manner for the dissipation of the increased heat generated in check straps, when used with the new high speed automatic looms, by taking advantage of the movements of the parts of these straps which are brought about by the checking action to force air through ventilating openings therein. It will be understood, of course, that the invention is not restricted to the particular method described of obtaining circulation of air through the ventilating openings in the check straps, but, so long as the movements of the parts of the strap which take part in the checking action of the air produce ventilation sufficient to dissipate the increased heat generated in high speed automatic looms, auxiliary circulating means will not be required.

What is claimed is:

1. A check strap of the loop type for high speed automatic looms, said strap having ventilating openings through said strap and distributed over the area of said strap beyond that in which the strap is secured to the loom.

2. A check strap according to claim 1 in which adjacent openings are offset from each other both transversely and longitudinally in said strap.

3. A check strap according to claim 1 in which the strap is of the type having parallel longitudinally curved edges whereby when looped it assumes a conical form which engages a picker stick throughout its width and thereby distributes the checking stress over its width.

4. A check strap according to claim 1 in which the strap is in the form of an endless rotating loop of frusto-conical shape.

HOMER J. SHIVELL.

REFERENCES CITED The following references are of record in the tile of this patent:

UNITED STATES PATENTS Number Name Date 408,663 Kelman Aug. 6, 1889 531,748 Raymond Jan, 1, 1895 1,095,947 Thorp May 5, 1914 1,529,588 Hanak Mar. 10, 1925 1,731,100 Herbener Oct. 8, 1929 1,927,305 Campbell Sept. 19, 1933 1,993,531 Shivell Mar. 5, 1935 2,236,488 Clark Mar. 25, 1941 2,289,240 Bullard July 7, 1942 2,290,238 Hickok July 21, 1942 2,290,685 Hickok July 21, 1942 2,429,348 Etchier Oct. 21, 1947 

